1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly to a semiconductor device including a semiconductor element.
2. Description of the Background Art
One of semiconductor elements is a thyristor, for example. The thyristor is attached to a predetermined circuit pattern formed on a printed circuit board of a control board part that controls the thyristor. Mounted on the surface of the printed circuit board are a capacitor, a transistor and the like constituting a control circuit element. An attachment plate is fixed to the control board part at a predetermined position in order to relay or fix an external power supply, a signal line and the like electrically connected to the control circuit element and the like.
The attachment plate is fixed by screwing a screw, inserted from the rear surface of the printed circuit board through a substrate through hole extending through a land of the printed circuit board, into a screw hole opened in the attachment plate. When applying power to the control circuit element and the like to operate them, the attachment plate needs to be electrically connected to the ground (ground potential) of the printed circuit board so as to block electric noise from the outside. For this reason, the attachment plate is electrically connected to the ground of the printed circuit board by implementing the screw by a metal screw. It is noted that Japanese Patent Laying-Open Nos. 2002-203931 and 2004-281743 disclose this kind of technical field.